Switch for potheads



March 19[ 1929.

F. F. BRAND SWITCH FOR BOTHEADS Filed Aug. 8, 1927 Patented Mar. 189, 1929.

UNITED STATES PATENT OFFICE,

FREDERICK E. BRAND, or PITTSFTELD, MASSACHUSETTS, ASSIGNOE. To GENERAL EEEC- TRIC COMPANY, A CORPORATION F NEW YORK.

v SWITCH EoEroTHEADs.

Appuea'nn filed August s,

" ground, is often connected to a terminal. of

such apparatus by a Switch or connector in a pothead mounted on the apparatus casing and containinginsulating oil or compound which surrounds and insulates the connector. It is customary to make vperiodic tests of a cableof this nature by applying to the cable 'conductor or conductors a voltage high enough to detect any weakness in the cable insulation. Vhile these tests are being made, the cable should be disconnected from other circuits and apparatus so that the results of the tests may not be affected by conditions outside the cable. It has been inconvenient, to make such tests, however, because the pot head cover had to be taken oii'and the oil or compound. removed ,before the connector could be opened and-the testing apparatus connected to the cable. The general object ofthe invention is to provide van improved switching arrangement for .potheads adapted to ermit disconnection and testing of a cable wit out opening the pothead'or removing any insulating oil or compound contained in the potliead.

The invention will be better understood from the following description taken in conu nection with the accompanying drawing in which Fig. 1 is a sectional view of a pothead I.' mounted on an electrical apparatus casing Y and provided withva switching arrangement in accordance with the invention, Fig. 2 is a sectional view of the pothead with the switch in open position, and Fig. Sis an enlarged sectional detail view. Like reference characters indicate similar is enclosed in the potliead` 10 to connect a "lead 14 from the electrical apparatus to theY conductor 15 of a cable 16 which also enters the pothead. The pothead may contain a body of insulating material such as oil or compound in which the switch 13 and the r terminals of the lead 14.3.1111 cable conductor I.testing apparat-us parts in the -diierent ligures of the .drawln'g 1927? serial No. 211,411.

15 are immersed. v The connecting blade of the sw1tch 13 has an arm 17 to the outer end of which 1s connected an operating rod 18. This operating rod 18 extends through a stuli ing bor 19 sealed onto the inner end of anV insulating bushing 20 mounted through an opening 1n the pothead 10. The length ot' the operating rod 18 is preferably such that 1t projects only a Short distance through the stufing box 19 so that its free or outer end 1s inside of and well protected by the bushing 20.-` A cap 21 may be secured over thev outer end of protection. During normal operation of the apparatus 1n the casing 11, the switch 13 is of course closed to connect the apparatus to the cable 16 as shown in Fig. 1. Vhen itis desired to testthe cable 16, it may be quickly and convenlent y disconnected from the apparatus 1n the casing 11 without the necessity of openlng the pothead by pulling the operatlng rod 18 to open the switch 13 as shown in Fig. 2. A handle 22 in the forni of an insulated rod may be conveniently used to openl or close'the switch 13, the adjacent ends of the handle 22 andthe rod 18 being arranged in any suitable way for detachable engagement ,as by being' threaded as shown most clearly in Figs. 2 and 3. The outer end Vot" the insulated rod 22 is provided withl a terminal'23 and the rods 22 and 18 and the arm 17 of the Switch are of 4conductive material so'that a conductive path is formedfromthe terminal 2 3 to the conductor 15 of thecable 16, the cable conductor being connected to the same Switch terminal which supports the connecting blade of the Switch and its arm 17. Thus,'a high volta e may be' conveniently applied to the terminal 23 by means of suitable to indicate the electrical condition of the -cable 16 and its insulation, thesyvgiftch- 13 having been first opened, of cour ,by `pulling the handle 22 outwardly so that the indications obtained from the testingapparatus may not be influenced by anythe bushing V for additional noY thing outside thel cable. After the testshave been completed, the cable may be againconnected. to the apparatus in the casing A"11 merely .b pushing in the handle 22 to close the switcii 13, the handle being then detached from the rod 18 and removed and the protective cover 21 replaced in position over the outer end of the bushing 20.

While the invention has .been explained by describing; and illustrating a preferred embodiment thereoi, it will be apparent that changes may be made without departing from the scope oit the invention as delined in the appended claims.

hat l claim as new and desire to secure by Letters lQatent of the UnitedStates is:

ll. The combination with electrical apparatus ot a pothead, a cable entering said pothead, a switch enclosed in said poth'ead tor connecting said cable tosaid apparatus, and conductive switch operating` means conductively connected to said cable while the switch is open and extending to a point accessible while said pothead is closed, wherebyT said cable may be disconnectedrfrorn said apparatus and tested without opening the pothead.

2. rlhe combination with electrical appa4 ratus oit a pothead, a cable entering said pothead, a switch enclosed in said pothead 'for connecting said cable to said apparatus,.a stuliing box carried by ly connected to said cable while the switch is open and extending throughsaid stuffing box to a point accessible from outside the pothead. p

3. The combination with electrical apparatus of a pothead, a cable entering said pothead, a switch enclosed in said pothead for connecting said cable to said apparatus, a

the pothead, and a conductive switch operating rod conductivemodico bushing extending through an opening in said pothead, a stufting boi; carried by said bush ing, and a conductive switch operating rod conductively connected to said cable while thc switch is open and extending into said bushing through the stuting box.

4l. 'llhe combination with electrical apparatus ot a pothead, a switch enclosed in said pothead Ytor connecting said cable to said ap paratus, a bushing extending through an opening in said pothead, a stutting boit carried by said bushing, a conductivc'switch operating rod extending through the stuflingbox and terminating within said bushing, and a conductive handle arranged for detachable engagement with the outer end of said switch operating rod.

5.V 'lhc combination with an electrical apparatus Casing, casing, an apparatus lead and a cable enter'- ing` said pothcad, a switch enclosed in said pothead for connecting said cable and said apparatus lead, and aconductive switch operating rod conductively connected to said cable while the switch is open and extending to a point accessible from outside said pothead while the pothead is closed.

In witness whereof, l have hereunto set my l hand this 28th day of July,`l927.

FREDERICK F. BRAND.

of a potheadA mounted on said f 

